is an option for Dataset that specifies the widths and heights of headers.


  • The setting for HeaderSize can be any size specification, or a pure function returning the same.
  • With the option HeaderSizesize, the specified size will be used for all headers in the dataset.
  • HeaderSizeAutomatic specifies a size automatically calculated to fit row or column contents.
  • The settings for HeaderSize can be given as follows to apply separately to different items:
  • specapply spec to all headers
    {spec1,spec2,,specn}apply speck to headers at Dataset level k
    {spec_(1),spec_(2),...,spec_(n), rules}also allow explicit rules for individual headers
  • The speck can have the following forms:
  • {s1,s2,,sn}use s1 through sn; then use defaults
    {{c}}use c in all cases
    {{c1,c2}}alternate between c1 and c2
    {{c1,c2,}}cycle through all ci
    {s,{c}}use s, then repeatedly use c
    {s1,{c},sn}use s1, then repeatedly use c, but use sn at the end
    {s1,s2,,{c1,c2,},sm,,sn} use the first sequence of si at the beginning, then cyclically use the ci, then use the last sequence of si at the end
    {s1,s2,,{},sm,,sn}use the first sequence of si at the beginning and the last sequence at the end
  • Rules have the form ispec, where i specifies a position in the dataset.
  • Positions can be patterns.
  • The position of a header can be read at the bottom of a dataset when you hover over the header.
  • If the left-hand side of a rule is not a list, the setting is applied to any position that contains the left-hand side as a key or index.
  • A pure function f that returns a size can be used in place of any size. The setting is given by f[item,position,dataset].


open allclose all

Basic Examples  (2)

Make all headers the same number of character widths wide:

Make row headers at least 4 character heights high, and columns at least 5 character widths wide:

Generalizations & Extensions  (1)

Use a pattern in a position:

Possible Issues  (1)

Displayed header sizes may be greater than specified sizes if headers must grow to accommodate lower-level rows or columns:

Introduced in 2020